Korgi

html-pipeline filters to generate urls for Rails resources.

# input
$+image.1$

# filtered result
/uploads/image/file/1/thumb_pic.jpg

korgi is meant to work with CarrierWave. You will need to tell korgi how to map resources for you:

# config/initializers/korgi.rb
Korgi.configure do |config|
  config.file_uploads = { image: { model: :Image, mount: :file, default_version: :thumb }
end

This tells korgi that you have a CarrierWave uploader mounted to Image on :file, with :thumb as its default version. You can then simply write $+image.1$ or $+image.1.large$ in your markdown input, and korgi will replace the syntax with the associated url (and version).

If you are using a Null Object Pattern, you can also set an optional nil_object for unavailable files to fallback for:

image: { ..., nil_object: :NullImage }

If you need the full url instead, you should change the settings for CarrierWave:

# config/initializers/carrierwave.rb
CarrierWave.configure do |config|
  config.asset_host = "http://awesome.host.com"
end

# filtered result
http://awesome.host.com/uploads/image/file/1/thumb_pic.jpg

# input
$#post.1$

# filtered result
/posts/1

You will need to tell korgi how to map resouces for you:

# config/initializers/korgi.rb
Korgi.configure do |config|
  config.named_routes = { post: { controller: :posts } }
end

In Rails speak, this means that korgi will replace $#post.1$ with the result of post_path(id: 1). If you are using FriendlyId to create url slugs, you can also do this:

# config/initializers/korgi.rb
Korgi.configure do |config|
  config.named_routes = { post: { controller: :posts, model: :Post, primary_key: :slug } }
end

This will enable korgi to interpret $#post.1$ as post_path(id: Post.find(1).slug) instead, and will then return the slugged url, e,g, /posts/slug-url.

I tried to keep korgi simple, so it only generates the link, not the entire html. You will most likely be using korgi along Markdown, but I'll leave that decision to you. Please do check out the documentation for html-pipeline on how to render Markdown content. Here is an example snippet:

pipeline =
  HTML::Pipeline.new [
    Korgi::FileUploadFilter,
    Korgi::NamedRouteFilter,
    HTML::Pipeline::MarkdownFilter
  ]
result = pipeline.call <<-EOD
This is a [link to post1]($#post.1$).
Here is an [image]($+image.1$).
EOD
result[:output].to_s

=>
<p>This is a <a href="/posts/1">link to post1</a>.</p>
<p>Here is an <img src="/uploads/image/file/1/thumb_pic.jpg" alt="image">.</p>

Send me a PR!

The gem is available as open source under the terms of the MIT License.